Air cargo is typically transported in containers (“Unit Load Devices”), or on pallets combined with nets, that are stowed in cargo holds either below the deck of passenger aircraft or below and above the deck in transport aircraft. The size and shape of cargo pallets vary depending upon the type of aircraft in use. In all aircraft, the gross weight of the airplane is a substantial factor, because of the cost of fuel.
Current air cargo pallets and containers are often made of aluminum skin on a hollow frame structure. A limited number have added bulsa wood or plywood cores, with very limited success. Such pallets are roughly handled and easily damaged when loaded into or unloaded from aircraft, and many problems therefore occur with such aluminum pallets. Aluminum pallets have various disadvantages, including their weight and their limited stiffness/weight ratio, thereby requiring additional weight distributing planks when carrying an unevenly distributed load.